<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="jquery-3.7.1.min.js"></script>
</head>
<body>
    <button id="btn">按钮</button>
    <ul>
        <li>item 1</li>
        <li>item 2</li>
        <li>item 3</li>
        <li>item 4</li>
    </ul>
    <script>
        //绑定事件处理器
        $("#btn").on("click",function(){
            console.log("事件触发了");
            
        })

        //事件委托
         $("ul").on("click","li",function(event){
            console.log("event.target");
         })
    </script>


</body>
</html>